Method for obtaining an oxidation inhibitor and an oxidation resistant lubricating oil



Dec. 4, 1956 PHENOL OIL CHARGE H. w. H. MEYER EI'AL 2,773,005 METHOD FOR OBTAINING AN oxxmmon mman'oa AND AN OXIDATION RESISTANT LUBRICA'IING on.

Filed Sept. 17. 1954 PHE/VOL 5 TR/PPER L DRUM 4 PHEIVOL 2 I STRIPPEI? INVEN T0115. I Herbert W hi Meyer, gdward E Wad/0y,

nited States atent METHOD FOR OBTAINING AN OXIDATION IN- HIBITOR AND AN OXIDATION RESISTANT LU- BRICATING OIL Herbert W. H. Meyer and Edward F. Wadley, Baytown, Tex., assignors, by mesne assignments, to Esso Research and Engineering Company, Elizabeth, N. J., a corporation of Delaware Application September 17, 1954, Serial No. 456,700

2 Claims. (Cl. 196-14.17)

The present invention is directed to a method for securing an oxidation inhibitor and to a method for obtaining an oxidation resistant lubricating oil from a paraffinic light motor oil feed stock derived from crudes such as Panhandle, Ellenberger, or Mid-Continent crudes.

Further objects and advantages of the present invention will be seen from the following description taken in conjuction with the drawing in which the sole figure is in the form of a diagrammatic flow sheet.

The charge stock employed in carrying out the present invention is preferably a Panhandle light motor oil. The characteristics of this stock are well known to the art. The material is a distillate fraction from crude petroleum oil produced from the Panhandle fields. The distillate fraction may boil within the range of 700 to 1000 F. although a heart cut fraction boiling in the range of 800 to 950 F. is preferred. It will be understood that hereafter when a Panhandle light motor oil is mentioned this material is being referred to.

Turning now specifically to the drawing, into countercurrent solvent extraction tower A is passed a Panhandle light motor oil charge stock through inlet line 11, phenol as the solvent extraction agent through inlet line 12 and water through inlet line 13. The solvent extraction of light lubricating oils by the use of phenol and Water is well known to the art. While the conditions may vary over a substantial range, it may be stated that in general the temperature should be in the range between the melting point of the solvent and the temperature at which complete miscibility occurs. In general, a temperature within the range of 160 to 220 F. will be preferred although a range from 110 to 260 F. may be employed if desired. The quantity of solvent used may also vary over a considerable range but in general it is preferred to use from .5 to 4.0 volumes of solvent per volume of oil.

From solvent extraction tower A a rafiinate fraction.

is removed through outlet line 14 and passed to stripper B where the phenol solvent is removed as overhead through line 15 and the rafiinate fraction, which is a desirable lubricating oil, is removed through outlet line 16.

An extract fraction is removed from solvent extraction tower A by means of outlet line 17 and passes to a separating zone C which may, for example, be a drum. From 3% to 6% water by volume based on the phenol extract is added through inlet line 18 to cause phase separation. Drum C is arranged to allow gravity settling therein so that the phases resulting from the addition of water to the phenol extract settle into layers which in drum C; consist of an oil rich layer 19 and a phenol rich (extract) layer 20.

When the bottom temperature of extract tower A is relatively high, it may be desirable to cool the solvent extract to a temperature within the range of 50 to 100 F. below the bottom temperature of tower A when carrying out the settling step in drum C.

The oil rich layer 19 is fed through line 19a to a stripping tower D where oil is withdrawn through line 21. A phenol fraction is removed in tower D through line 22.

As an alternative procedure, the oil fraction 19 maybe passed through open valve 10 of line 9as reflux to tower A.

The phenol or extract layer 20 formed in drum C is withdrawn through line 23 and passed to stripper E where it is separated into a phenol fraction removed through line 24 and a finished extract fraction removed through line 25.

The extract fraction removed from stripper B through line 25 has been found to be particularly eifective for use as an oxidation inhibitor for lubricating oils preferably in amounts within the range of about 0.2% to about 5% by volume. A portion is advantageously admixed with the raflinate fraction removed from extract tower A to produce an oxidation resistant lubricating oil. Thus, if desired, the finished extract fraction from line 25 may be removed from the system through line 26 for admixture in a desired lubricating oil or alternatively may be passed through line 27 for admixture with the finished rafiinate fraction in line 16, lines 26 and 27 being provided with valves 26' and 27', respectively, to control the flow of the oxidation inhibiting material as desired.

In order to illustrate further advantages of the present invention, the following example is given:

EXAMPLE An extract from Panhandle light motor oil was secured by extracting with phenol and water to separate a rafiinate fraction and an extract fraction and water then added to the extract fraction to cause phase separation into a phenol fraction and a separate extract fraction in accordance with the procedure described in conjunction with the drawing. A white oil sample was divided into two equal fractions. The first fraction designated A in the table hereafter set out was used as a control while the second fraction, designated as B in the table hereafter had added thereto 1% by volume of the second extract. Samples A and B were both subjected to oxidation by means'of a standard test common to manufacturers of lubricating oils. This test is the Indiana Life Test and is conducted by bubbling air at a rate of 10 liters/hr. through a 300 vol. sample of oil maintained at a constant temperature of 341 F. After 48 hours the oil sample was withdrawn and tested and the results of the tests were as follows:

The invention claimed is:

1. A method for obtaining an improved oxidation resistant lubricating oil including the steps of extracting in a first extraction zone in the presence of phenol and water a paraflinic light motor oil distillate to separate it into an extract phase and a rafiinate phase, removing said raifinate phase from said first extraction zone and stripping phenol therefrom to recover a motor oil fraction, removing the first extract phase from said first extraction zone, passing it to a separation zone and there adding from 3% to 6% by volume water thereto to cause phase separation therein to form a second extract fraction and a second raflinate fraction, separately removing said second extract fraction and said second raffinate fraction from said separation zone, stripping the phenol from said second extract fraction to recover a finished oxidation inhibitor and admixing at least a portion of said finished Patented Dec. 4, 1956 oxidation inhibitor with said motor oil fraction to recover References Cited in the file of this patent a finished oxidation resistant lubricating Oil. UNITED STATES PATENTS 2. A method as recited in claim 1 wherein the portion of oxidation inhibitor admixed with the motor Oil frac- 2,215,359 Llvmgsmn tion is in the range of about 0.2% toabout 5% by volume 5 fth t 1f ti 0 e mo m on 2,327,158 V011 Fuchs Aug. 17, 1943 

1. A METHOD FOR OBTAINING AN IMPROVED OXIDATION RESISTANT LUBRICATING OIL INCLUDING THE STEPS OF EXTRACTING IN A FIRST EXTRACTION ZONE IN THE PRESENCE OF PHENOL AND WATER A PARAFFINIC LIGHT MOTOR OIL DISTILLATED TO SEPARATE IT INTO AN EXTRACT PHASE AND A RAFFINATED PHASE, REMOVING SAID RAFFINATE PHASE FROM SAID FIRST EXTRACTION ZONE AND STRIPPING PHENOL THEREFROM TO RECOVER A MOTOR OIL FRACTION, REMOVING THE FIRST EXTRACT PHASE FROM SAID FIRST EXTRACTION ZONE, PASSING IT TO A SEPARATION ZONE AND THERE ADDING FROM 3% TO 6% BY VOLUME WATER THERETO CAUSE PHASE SEPARATION THEREIN TO FORM A SECOND EXTRACT FRACTION AND A SECOND RAFFINATE FRACTION, SEPARATELY REMOVING SAID SECOND EXTRACT FRACTION AND SAID SECOND RAFFINATE FRACTION FROM SAID SEPARATION ZONE, STRIPPING THE PHENOL FROM SAID SECOND EXTRACT FRACTION TO RECOVER A FINISHED OXIDATION INHIBITOR AND ADMIXING AT LEAST A PORTION OF SAID FINISHED OXIDATION INHIBITOR WITH SAID MOTOR OIL FRACTION TO RECOVER A FINISHED OXIDATION RESISTANT LUBRICATING OIL. 